This can be fun when after booting a default USA keyboard is used. Where are the PLUS and MINUS keys if you are using a UK keyboard? Perhaps between ZERO and BACKSPACE on the top row, or try the numeric keypad. Does your keyboard have a EURO key? Perhaps AltGr+E perhaps not.
Central and eastern European QWERZ countries tend to celebrate Xmas on the 24th of December, Christmas Eve; English-speaking QWERTY countries on the 25th.